Android UIDs

1. Android does not have /etc/passwd, /etc/shadow, and /etc/group files.
2. The file named android-filesystem-config.h in the AOSP source tree has the equivalent defines.
3. E.g.,
   1. #define AID_ROOT 0 /* traditional unix root user */
   2. #define AID_GPS 1021 /* GPS daemon */
4. % adb shell The rest of what is shown below is within AVD pmNX5a.
   1. root@generic:/ # ls -l /acct/uid shows "uid" directories
   2. root@generic:/ # more /data/system/packages.list shows how the application name is tied up with uid/gid.
   3. Ex: com.android.keyguard 10007 0 /data/data/com.android.keyguard platform 1028,1015,1035,3002,3001
5. Every app gets its own uid, distinct from all other apps. App uid do not remain the same across all Android devices.